Composition, optical compensatory film and liquid crystal display

Abstract

A composition comprising at least one compound having a fluoro-aliphatic group and at least one hydrophilic group selected from the group consisting of a carboxyl group (—COOH), a sulfo group (—SO 3 H), a sulfato group (—OSO 3 H), a phosphonoxy group {—OP(═O)(OH) 2 } and salts thereof; at least one onium salt; and at least one liquid-crystal compound is disclosed.

1. An optical compensatory film comprising at least one optically anisotropic layer formed of a composition comprising:
 at least one compound having a fluoro-aliphatic group and at least one hydrophilic group selected from the group consisting of a carboxyl group (—COOH), a sulfo group (—SO 3 H), a sulfato group (—OSO 3 H), a phosphonoxy group {—OP(═O)(OH) 2 } and salts thereof; 
 at least one onium salt; and 
 at least one liquid-crystal compound; 
 wherein the compound having a fluoro-aliphatic group and at least one hydrophilic group is a compound represented by Formula (2b):
   (R 7 —L 1 —) m2 (Ar 1 —)—W 3   
 
 R 7  represents an alkyl group, an alkyl group having a terminal CF 3  group or an alkyl group having a terminal CF 2 H group; m2 denotes an integer greater than or equal to 1, wherein multiple occurrences of R 7  may be identical or different, with at least one representing an alkyl group having a terminal CF 3  group or a terminal CHF 2  group; L 1  represents a divalent linking group selected from the group consisting of an alkylene group, an aromatic group, —CO—, —NR— wherein R denotes a C 1-5  alkyl group or a hydrogen atom, —O—, —S—, —SO—, —SO 2 — and any combination thereof, where multiple occurrences of L 1  may be identical or different; Ar 1  represents an aromatic carbon ring residue or an aromatic hetero ring residue; and W 3  represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO 3 H) or a salt thereof, a sulfato group (—OSO 3 H) or a salt thereof, or a phosphonoxy group {—OP(═O)(OH) 2 } or a salt thereof; 
 the onium salt is a quaternary ammonium salt; and 
 the liquid-crystal compound is a discotic compound and molecules of the discotic compound are substantially aligned vertically in the optically anisotropic layer. 
 
     
     
       2. An optical compensatory film comprising at least one optically anisotropic layer formed of a composition comprising:
 at least one compound having a fluoro-aliphatic group and at least one hydrophilic group selected from the group consisting of a carboxyl group (—COOH), a sulfo group (—SO 3 H), a sulfato group (—OSO 3 H), a phosphonoxy group {—OP(═O)(OH) 2 } and salts thereof; 
 at least one onium salt; and 
 at least one liquid-crystal compound; 
 wherein the compound having a fluoro-aliphatic group is a copolymer comprising a repeating unit derived from a monomer having a fluoro-aliphatic group and a repeating unit represented by Formula (1): 
 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2  and R 3  respectively represent a hydrogen atom or a substituent; L represents a divalent linking group selected from the Linking Group shown below or a divalent linking group consisting of two or more selected from the Linking Group shown below; 
       
       (Linking Group)
 a single bond, —O—, —CO—, —NR 4 — where R 4  represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, —S—, —SO 2 —, —P(═O)(OR 5 )— where R 5  represents an alkyl group, an aryl group or an aralkyl group, an alkylene group and arylene group; 
 Q represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO 3 H) or a salt thereof, a sulfato group (—OSO 3 H) or a salt thereof, or a phosphonoxy group {—OP(═O)(OH) 2 }or a salt thereof; 
 the onium salt is a quaternary ammonium salt; and 
 the liquid-crystal compound is a discotic compound and molecules of the discotic compound are substantially aligned vertically in the optically anisotropic layer. 
 
     
     
       3. A liquid crystal display comprising, in this order:
 a first polarizing film, 
 an optical compensatory film comprising a first retardation-area contacting with the first polarizing film and a second retardation-area contacting with the first retardation-area, and 
 a liquid-crystal cell comprising a pair of a first and a second substrates and a liquid crystal layer formed of a nematic liquid-crystal material sandwiched in between the pair of the substrates, and molecules of the nematic liquid-crystal being parallel to surfaces of the pair of substrates in a black state; 
 wherein the first retardation-area has an in-plane retardation value, Re, of not greater than 20 nm; and a retardation value in thickness direction, Rth, falling with in a range from 20 to 120 nm; 
 the second retardation area comprises an optically anisotropic layer which is formed of a composition comprising at least one compound having a fluoro-aliphatic group and at least one hydrophilic group selected from the group consisting of a carboxyl group (—COOH), a sulfo group (—SO 3 H), a sulfato group (—OSO 3 H), a phosphonoxy group {—OP(═O)(OH) 2 } and salts thereof; at least one onium salt; and at least one discotic liquid-crystal compound; and in which molecules of the discotic liquid-crystal compound being substantially aligned vertically; and 
 a slow axis of the second retardation-area is parallel to both of a transmission axis of the first polarizing film and a slow axis of the liquid crystal layer in a black state. 
 
     
     
       4. The liquid crystal display of  claim 3 , comprising a second polarizing film disposed outside of the second substrate. 
     
     
       5. The liquid crystal display of  claim 3 , wherein the second retardation-area has Re falling with in a range from 50 to 200 nm. 
     
     
       6. The liquid crystal display of  claim 3 , wherein the first retardation-area comprises plural layers and one layer of the plural layers contacting with the second retardation-area is an alignment layer. 
     
     
       7. The liquid crystal display of  claim 3 , comprising a pair of protective layers sandwiching the second retardation-area, wherein one of the protective layers disposed nearer to the liquid-crystal layer than another has Rth not greater than 20 nm. 
     
     
       8. The liquid crystal display of  claim 3 , comprising a pair of protective layers sandwiching the second retardation-area, wherein one of the protective layers disposed nearer to the liquid-crystal layer than another is a cellulose acylate film or a norbornene or norbornene-derivative film. 
     
     
       9. The liquid crystal display of  claim 3 , comprising a pair of protective layers sandwiching the second retardation-area, wherein one of the protective layers disposed nearer to the liquid-crystal layer than another comprises a cellulose acylate film and a layer comprising a rod-like liquid-crystal compound aligned vertically. 
     
     
       10. The liquid crystal display of  claim 3 , wherein the first retardation-area comprises plural layers and one layer of the plural layers contacting with the first polarizing film is capable of being a protective layer of the first polarizing film.